With the help of native Cheyenne researchers, we propose to examine government census documents from the early reservation period to answer some fundamental sociological questions about family structure in tribal societies generally and about the Southern Cheyennes in particular. In general we are interested in social polarization as a prelude to a change from uterine to agnatic or cognatic social forms. We are also interested in the effects of land attrition and economic change on family and band structure, and on vital rates. In particular we will investigate the division of Cheyenne society into patrilocal and matrilocal bands, the presence of contrasting social and demographic features among the families and bands, the differential acculturation of the bands, and the social consequences of allotment in severalty. A wealth of data and new cybernetic techniques enable us to control a solution to these problems. The processed data resulting from this project will benefit Cheyenne people in their legal claims and genealogical inquiries.